DMD and myasthenia gravis: Serum GDF15 was elevated in 15 patients (upper limit 297.568 pg/ml), including 8 patients with epilepsy (8/15, 53%), 3 patients with myasthenia gravis (3/6, 50%), 3 patients with DMD (3/7, 42.9%), and 1 patient with viral encephalitis (1/2, 50%).